Currently, the driving voltage of a TFT-LCD (Thin Film Transistor-Liquid Crystal Display) is a fixed value which is usually AVDD. A source driver IC finally forms gray scale voltages by performing computation on the driving voltage (AVDD), a common voltage (VCOM) and Gamma voltages, in order for the TFT-LCD to realize display of different gray scales. When the environment temperature of the TFT-LCD changes, deflection angles of the same gray scale voltage for liquid crystal (LC) molecules are different, resulting in change of the display brightness and the contrast of the TFT-LCD, which is reflected by the Gamma voltage values on the Gamma gray scale curve deviating from the design values. In particular, when the temperature drops, the LC viscosity increases, and if it is under the effect of the same driving voltage, the LC response time will be longer. Therefore, in order to deflect the LC molecules to the same angle as at the normal temperature, the electric field force required at this time will be increased, that is, larger gray scale voltage is needed. Therefore, with the change of temperature, the driving voltage of the TFT-LCD is correspondingly modified, to compensate for the temperature and alleviate the poor display caused by the temperature change.
Currently, the temperature compensation for the TFT-LCD is realized most by thermosensitive resistors or resistance temperature sensors. Such a method is realized specifically by using the linear relationship between the resistance of the resistor and the temperature change. However, in general, the response time of the LC molecules is not in linear relationship with the temperature change, that is, when the same gray scale is displayed, the electrical field force required by the LC is not in linear relationship with the temperature change. Therefore, it is not possible to realize good temperature compensation for the TFT-LCD by using thermosensitive resistors or resistance temperature sensors.